Can Australia overcome its water scarcity problems?
Colin Chartres(1) and John Williams(2)
(1)

(2)

Science Advisor, National Water Commission, 95 Northbourne Avenue, Canberra, ACT
2600, Australia (also CSIRO Land and Water, GPO Box 1666, Canberra ACT 2601,
Australia)
Chief Scientist, NSW Department of Natural Resources, 23-33 Bridge St., Sydney, NSW
2000 and Member of the Wentworth Group of Concerned Scientists.

Abstract
Australia is a continent of extremes with respect to water resources; relative abundance in thetropical north where few people live and relative scarcity in the more populated, temperate south.
In addition, both south and north are affected by wet/dry seasonal climatic conditions and thesouth, in particular, by increasing climate variability marked generally by declining rainfall. In
the south, previous poor governance systems have led to the over allocation of surface andgroundwater supplies and there is increasing competition for water from irrigators,
urban/domestic, industrial and mining users. As a consequence, there has been a majordeleterious impact on the health of many rivers and their associated environments. So, Australia
is confronted with a major question; can water productivity and water governance be improved
to ensure environmentally sustainable and productive river systems? This paper examines how
this may be achieved. It concludes that economic reforms coupled with scientific andmanagement innovation may alleviate many of the water scarcity issues.

Water Resources in Australia
Water scarcity is becoming an increasingly significant problem for many countries. According
to an International Water Management Institute definition, a very significant portion of the worldis projected to suffer from both physical (<1000 m3 per person/annum) and economic water
scarcity by 2025. Whilst Australia’s water resources are well in excess of this per capita

1definition of scarcity there is growing concern that export of “virtual water” in food may be to
the detriment of our environment.

COUNTRYRIVER

RATIO BETWEEN
THE MAXIMUM andthe MINIMUM
ANNUAL FLOWS

Switzerland
China
Sudan
USA
South Africa
Australia
Australia

Rhine
Yangtze
White Nile
Potomac
OrangeMurrayHunter

1.9
2.0
2.4
3.9
16.9
15.5
54.3

Table 1. Variability of flow in some of the world’s major rivers compared with twoAustralian rivers.
Australia’s water resources are highly variable (Table 1), and reflect the range of climaticconditions and terrain nationally. In addition, the level of development in Australia’s water
resources ranges from heavily regulated rivers and groundwater resources, through to rivers andaquifers in almost pristine condition. Over 65% of Australia’s runoff (Fig. 1) is in the threedrainage divisions located in the sparsely populated tropical north. In contrast, most large urban
cities are situated in southern regions with irrigated agriculture principally located in the Murray
Darling Basin where only 6.1% of national run-off occurs. Thus Australia has significant water
resources, but the populations and agricultural activities are concentrated where water resources
are most limited. Australia has around 440,000 gigalitres (GL) of water. The best estimate of
how much water can be diverted and turned to human use is approximately 105,000 GL (Table
2).
At present, Australians extract about 70,000 GL and consume about 22,200 GL, of which 15,500
is used in agriculture. But the consumption in irrigated agriculture is increasing (Fig. 2) —by
about 15 percent in the past three years—and as agriculture consumes 70 percent of the water
resource Australian agriculture must learn how better to turn that scarce water into wealth andwellbeing for our communities.

2

Total run-off

440,000 GL (divertible 105,000 GL)

Water extracted

70,000 GL

Water consumed

22,178 GL•

agriculture

15,522 GL•

households

1,829 GL•sewerage and drainage

1,707 GL•

mining and manufacturing

1,289 GL•

Electricity and Gas

1,308 GL•

Other

523 GL

Table 2. Water in Australia 1993–1997 (Source: ABS website, May 2000)

20.3%
23.3%

0.4%

21.1%

1.9%
0.3%

1.7%

0.3%
6.1%
10.6%
13.3%

Figure 1. Australia’s distribution of run-off (Source: Water and theAustralian Economy, April 1999)
Two million hectares of Australia (<1% of the land surface) is irrigated and this generates about
50 percent of our profit from agriculture. Nearly 75% of this irrigated agriculture occurs in the3Murray-Darling Basin where water demand and levels of water extraction from rivers andgroundwater are now unsustainable. About 75% of the mean annual flow in the basin is divertedwith the result that the mouth of the Murray has often closed in recent years of lower rainfall. To
cope with climate variability more than twice the average annual flow in the basin is held instorages (Fig.3). Such high level of storage and extraction have very damaging impacts on theheath of the rivers, floodplains, wetlands and estuaries of the Murray –Darling. Recognising thisin 1994, Australians ruled a line and agreed to cap extractions at 1995 levels (Fig. 4). This was
one of the first and most important policy decisions in the Murray-Darling, which recognisedthat the limits of sustainability had been overreached.
The major challenge facing Australia is that of balancing water extractions for irrigation andother uses with provision of appropriate environmental flow to maintain healthy rivers and thus
service the needs of all users of rivers and groundwaters. Experience demonstrates that if
regulators place a cap on surface water, demand is transferred to groundwater. However, in
reality surface and groundwater needs to be managed conjunctively. While returning increased
flows to rivers in southern Australia is a major challenge, and absolutely critical to river system
health, many other land management factors such as, drainage; nutrient and chemical pesticides
loading are very important to the health and ecological function of rivers, groundwaters,
wetlands, floodplains and estuaries.
Potential Impacts on Water Resources of changes in Climate and Land Use
Climate Change and Variability
Climate change projections (as summarized by Hennessy, 2003) for Australia show increased
potential evaporation, a tendency for decreases in winter-spring rainfall (June–November) overthe southern half of the continent and a tendency for increased summer/autumn rainfall(December–May) in northern Australia. The possibility of a longer and more intense Australian4

Figure 2. Development of irrigated areas in Australia

Figure 3. Storage capacity and diversions in the Murray-Darling Basin from 1920 to 2000.

Figure 4. Growth in water use in Murray-Darling Basin 1920 to 2000.

5

monsoon would lead to greater water surpluses in an area where human use is low, so
environmental flows would be enhanced. In southern Australia, where winter and spring rainfall
are more important and competition for water between natural and human uses is already high,reductions in water supply appear to be much more likely with the possible exception of
Tasmania.
Climate change and Australian natural climate variability are inextricably linked and while theunderpinning science of climate change is solid, much remains to be understood (Pearman andHennessy, 2003). This inextricable link between natural long term variability and drivers ofclimate change is well illustrated (Fig. 5) by the 100 years data set for the Warragamba Dam, themajor water supply to Sydney. Since the construction of the Warragamba Dam between 1948
and 1960 the 7 year moving average rainfall and run off to the dam have been declining to levels
that appear to be consistent with pre 1950 moving averages. A return to inflow to the dam
similar to this 1900-1950 period will present real difficulties for Sydney’s water supply. It is
onto this high variable and cyclic pattern of rainfall that climate change (both magnitude andvariability) is to express itself.

Figure 5. Rainfall and Runoff in Warragamba catchment from 1900 to 2003 (source Cox ,
2005)

6

The evidence is that climate change will increase the difficulty Australia faces in securing
adequate water supplied for cities and irrigation

Change in Vegetation Cover and land Use
There has been a surge of investment and activity in plantations, farm forestry and generalrevegetation in Australia. The essential design criterion of sustainable farming is to ensure that
present day flows of water, nutrient, carbon and energy match the magnitude of the flows thatevolved to suit the way our landscape functions. This will require some radical change to landuse, incorporating both commercial tree production and revegetation with tree-dominant native
vegetation. Plantation and farm forestry, agro-forestry, new agricultural production systems andrestoring native vegetation present opportunities to create a landscape with a mosaic ofvegetation that has a similar water-use pattern to the original native vegetation. This future
landscape has the potential to both treat the cause of land and water degradation problems andgenerate wealth sufficient to sustain viable rural communities. Most importantly, this tree-based
mosaic has the potential to maintain and enhance biodiversity and delivers a suite of ecosystemservices, including carbon sequestration, habitat diversity, salinity control and clean water.
Recent synthesis (CSIRO, 2004) acknowledged that concerns have arisen that, in some situations,
expansion of forestry on a large scale could diminish flow to streams and groundwater andthreaten water availability or water quality. Competition for water resources between forestry,
revegetation with tree-dominant native vegetation and other uses can lead to disruption ofindustries and resource development, as well as community conflict.
The Water Reform Process in Australia
Water in Australia is vested in the State and Territory governments which allow other parties toaccess and use water for a variety of purposes, including for irrigation, mining and otherindustrial uses, and servicing rural and urban communities. As demonstrated previously, by the7second half of the last century, it was clear that natural equilibria essential to the healthyfunctioning of the natural resource base had been upset by over exploitation of our natural
resources. In 1994, all State and Territory governments agreed on a package of reforms
covering water prices, allocations and trading, environmental and water quality, and public
education. In agreeing to the reforms, the governments formally acknowledged, for the first time,that Australian rivers, catchments and aquifers do not stop at state boundaries and thatdevelopment activity in one state can have impacts in other states.
By the late 1990s the Australian Government was sufficiently concerned by the range, breadthand cost of land and water degredation problems that it commissioned a nationwide National
Land and Water Resources Audit (NLWRA 2002) that showed that 26% of Australia’s surface
water management areas and some groundwater management units were either close to, or
overused compared with their sustainable flow regimes.
More recently high levels of water extraction and few, if any, natural flood events have put
further stress on the River Murray. In 2003 this was recognised with “The Living Murray”
initiative aimed at returning 500 GL of water to the river for environmental flow purposes.
The Council of Australian Government’s (CoAG) latest response to ongoing water issues has
been to develop an intergovernmental agreement called the National Water Initiative (NWI).
The NWI was signed in recognition of the continuing national imperative to increase theproductivity and efficiency of Australia’s water use, the need to service rural and urban
communities, and to ensure the health of river and groundwater systems. It is a comprehensive
package of reforms related to water entitlements, trading and sustainable use.

Responses and opportunities related to water scarcity
Southern Australia, at least, is faced with dealing with the ramifications of growing population,
variable climate and increasing water scarcity. To cope with these the reform process has to8include incentives that improve water use efficiency and productivity. Thus the NWI is
stimulating and guiding the following developments in water management:
Whole-of-system thinking
Many water scarcities have developed because our management has failed to apply whole-ofsystem thinking to water supply, re-use, consumption and return of water to natural water bodies.
Stream flow and groundwater are often managed as independent entities as are urban storm
water and sewage treatment and effluent re use. Progress in Australia has built on taking an
integrated approach underpinned by recognition of interactions in the water cycles (Fig. 6). For
example, rivers are stressed by being dammed and regulated, and by water extraction, when thepattern of flow is changed. Over-extraction of water can endanger native fish, increase salinity
and the incidence of algal blooms, and damage vegetation in wetlands and floodplains. Changes
in river flow regimes affect groundwater recharge and discharge patterns to and from wetlands,
billabongs and flood plains. The death of Red River gums in the billabongs and floodplains somedistance from the Murray River is the result of declining and increasingly saline groundwaterand lack of fresh water recharge.
Integrated catchment management is now an operating principle for the implementation of
CoAG’s water reform initiatives and is central to the establishment of catchment management
authorities in Victoria and New South Wales and similar structures in the other states. Regional
management of catchments using many of the conceptual frameworks that have evolved from awhole-of-system approach are now established practice.
Technical Innovation
Technical innovation in the water industry encompasses a wide range of possibilities including
more effective and cheaper ways of treating waste and saline water for reuse, improved leakdetection systems for urban and irrigation water conveyance systems, the use of solar energy todesalinate water, remote sensing technologies that improve our understanding of the distribution

9

CLIMATE VARIABILITY and CHANGE
RainfallIRRIGATIONorURBAN CENTRE

CATCHMENTGROUNDWATERDAMWETLANDSEAESTUARY

RIVER

Figure 6. Water flows to be managed in irrigation within a whole of system approach.
vertically and horizontally of fresh and saline water resources, improved modelling of water
systems that facilitates adaptive management responses and engineering improvements that
reduce the amounts of water required to process materials in mining, agricultural value adding
and manufacturing.
Urban systems
Limited sites for new dams and climate variability mean that Australian urban communities needto increasingly look at using water more efficiently and to conserve scarce supplies. In 2003,
water usage in Australia’s 22 largest cities was 2,065 GL of which 59% was residential and 28%
was used for industrial, commercial, local government, parks and fire fighting. Nationwide
about 9% of total effluent was reported as being recycled. In 2001/02, over 500 sewage treatment
plants nationwide contributed to this recycling of less than 200 GL per year. Demand andpricing management have meant that Sydney, for example, has been able to accommodate
population growth. Until 1985 population growth and water consumption paralleled each other(Fig. 7). However, subsequently consumption flattened off enabling the city to accommodate an
extra 700,000 people without growth in water demand. Thus we have built major infrastructure

10and enabled Sydney to grow by 3 million people during what appears to be a rainfall sequencethat is much wetter than the first 50 years since federation in 1901.
A number of other initiatives that go under the umbrella headings of “integrated water systemmanagement” and “water sensitive urban design” include opportunities to incorporate third pipe
“grey” water systems for toilet flushing and garden watering in new housing developments,
increased treatment of effluent and its reuse for industry and irrigation, sewer mining andtreatment for localised irrigation of parks and sports grounds and stormwater capture andtreatment to substitute for potable water in a wide range of non potable uses. However, nonpotable reuse is still face with considerable regulatory hurdles to overcome. Socially andpolitically substitution of drinking water by treated effluent and stormwater for non potable uses
has a lot of scope to alleviate the demand for new potable supplies. However, indirect potablereuse of treated sewage, will in some instances have to be considered.

Water use efficiency and productivity gains
As elsewhere in the world, Australia’s irrigation systems suffer from problems associated with

Figure 7. Sydney’s water supply in relation to its population growth (after WSAA, 2005).

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losses in storage and conveyance, on-farm losses and variable water use efficiency. The Murray
Darling Basin Commission has demonstrated that for the basin as a whole, 25% of diversions for
irrigation are lost during conveyance in rivers, 15% are lost from canals and 24% lost on farm,meaning that only 36% of irrigation water is actually delivered to plants. Such losses are not
atypical across the world. The data for the Murrumbidgee Irrigation Area (MIA) (Table 5) do notinclude river conveyance losses and indicate on farm losses better than the overall MDB average.
Simply increasing water use efficiency (WUE) is not the solution to better use of irrigation water.
Technically WUE tells us how much water is consumed by the crop and how much wasted.
However, the real wastage comes from not being as productive as possible with the water that isconsumed. Efficiency can be high with consequent detrimental environmental consequences,whilst productivity is low. Growing more food with less water alleviates scarcity, contributes tofood security and puts less strain on nature. The most effective way to increase waterproductivity is to shift water use by trading from low value to high value crops. To facilitate this,water entitlements, trading regimes, market factors and other complicated issues such as
stranding of assets all have to be taken into account.
Over the last 60 years, Australian agricultural productivity in dryland and irrigated systems has
increased on average by 3% per annum (Knopfke et al. 2000). This has kept Australian farmers
internationally competitive in the face of declining terms of trade for agricultural products andsubsidies on agricultural production offered by some competitors.
Key Indicators

Area (ha)Liuyuankou

Rechna Doab

MIA

China

Pakistan

Australia

40,7242,970,000

156,605

41
15
32

12
11
77

Losses from Supply System %35
Field Losses %18
Net Surface Water available to 46
crop %

Table 5 Surface water irrigation efficiency (personal communication Shahbaz Khan)

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Whilst many of these improvements have come from plant breeding, disease and pest
management and soil and fertility management, improved use of available water has also beenvery important. For example, the productivity of Australian rice production has increased fromabout 0.4 g/Kg of water used to 0.8 g/Kg over the last 20 years with a concomitant reduction inwater used from about 1600 to 1250 litres/Kg (Fig. 8). These figures demonstrate that riceproduction in Australia is one of the most efficient users of water for rice production in the world.

mm
1600

g/kg
1.6

1200

1.2

800

0.8

400

0.4
Measured field water use

Water productivity

0.0

0
1980

1984

1988

1992

1996

2000

Figure 8. Rice irrigation water use efficiency trend –Murrumbidgee Irrigation Area
(MIA) (source:CRC for Rice Production)

Conclusions
Australia is at a crossroads in terms of its ability to cope with increasing water scarcity. A
vigorous reform process is underway that is focusing on governance, productivity andenvironmental issues. This will require a level of commitment by state and federal governments
to drive the reforms and oversee a major re-allocation of water between irrigation activities, from
irrigation to river and groundwater flow and some movement of water from irrigation to urban
use. Within irrigation water will tend to move away from low value production for water use tohigher value production. If reforms allow third party access to urban sewage and effluents there
will be incentives for innovation in re-cycling and greatly increased water re-use. The capacity to
manage periods of adjustment, including through water trading, will be difficult but critical to13

success. If the reforms are able to establish a framework that allows water to trade andeconomic incentives develop that encourage and support innovation then we can expect to see asignificant increase in water productivity across industries while returning sufficient water to ourstressed rivers, floodplains, wetlands and estuaries. They may also enable us to avoid mistakes
made in the south as our northern rivers come under increasing development pressure.

References
Cox, D. 2005 Overview of Water Resource Management in Australia. In Role of Irrigation in
Urban Water Conservation: Opportunities and Challenges. CRC Irrigation Futures, 2005/1.
CSIRO. 2004 Maximising the benefits of new tree plantations in the Murray-Darling Basin .A
joint statement by CSIRO Forestry and Forest Products and CSIRO Land and Water available at
http://www.clw.csiro.au/new/FFP-LW19052004.pdf
Hennessy, K. 2003 Climate Change and its projected Effects on Water Resources Proceedingsof the 2003 Invitation Symposium, WATER- The Australian Dilemma, Academy ofTechnological Sciences and Engineering. Canberra. p.174 (available
http://www.atse.org.au/uploads/Hennessy03.pdf)
Knopke, P. O’Donnell, V and Shepherd A. 2000. Productivity growth in the Australian Grains
Industry. ABARE Research report 2000.1 Canberra.
NLWRA. 2002. Australia’s Natural Resources 1997 – 2002 and beyond. Nation Land and Water
Resources Audit, Commonwealth of Australia, Canberra.
Pearman, G. I., and Hennessy, K. J. 2003. Climate science: what do we know? In: Living withclimate change: a national conference on climate change impacts and adaptation: proceedings,
Australian Academy of Sciences. Canberra: National Academies Forum. p. 3-31.
http://www.dar.csiro.au/publications/pearman_2003a.pdf
WSAA. 2005. Testing the Water. Urban water in our growing cities: the risks, challenges,
innovation and planning. Water Services Association of Australia. WSAA Position Paper No. 1.
(http://www.wsaa.asn.au)

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